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United States Patent |
5,705,164
|
Mackey
,   et al.
|
January 6, 1998
|
Lotioned tissue paper containing a liquid polyol polyester emollient and
an immobilizing agent
Abstract
A lotion composition for imparting a soft, lubricious, lotion-like feel
when applied to tissue paper in amounts as low as from about 0.1 to about
15% by weight, and tissue paper treated with such lotion compositions are
disclosed. The lotion composition comprises a liquid polyol polyester
emollient and an immobilizing agent to immobilize the liquid polyol
polyester emollient on the surface of the tissue paper web and optionally
a hydrophilic surfactant to improve wettability when applied to toilet
tissue. Because less lotion is required to impart the desired soft,
lotion-like feel benefits, detrimental effects on the tensile strength and
caliper of the lotioned paper are minimized or avoided.
Inventors:
|
Mackey; Larry Neil (Fairfield, OH);
Roe; Donald Carroll (West Chester, OH)
|
Assignee:
|
The Procter & Gamble Company (Cincinnati, OH)
|
Appl. No.:
|
510935 |
Filed:
|
August 3, 1995 |
Current U.S. Class: |
424/400; 424/401; 424/402 |
Intern'l Class: |
A61K 009/00 |
Field of Search: |
424/400,401,402
|
References Cited
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|
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3619280 | Nov., 1971 | Scheuer | 117/154.
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|
3814096 | Jun., 1974 | Weiss et al. | 128/260.
|
3818533 | Jun., 1974 | Scheuer | 15/104.
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3821068 | Jun., 1974 | Salvucci et al. | 162/111.
|
3896238 | Jul., 1975 | Smith | 424/358.
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3896807 | Jul., 1975 | Buchalter | 128/260.
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3916058 | Oct., 1975 | Vossos | 428/241.
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3965518 | Jun., 1976 | Muoio | 15/104.
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3974025 | Aug., 1976 | Ayers | 162/113.
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4005195 | Jan., 1977 | Jandacek | 424/180.
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4005196 | Jan., 1977 | Jandacek et al. | 424/180.
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4085052 | Apr., 1978 | Murphy et al. | 252/8.
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4103047 | Jul., 1978 | Zaki et al. | 427/242.
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4112167 | Sep., 1978 | Dake et al. | 428/154.
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4142978 | Mar., 1979 | Murphy | 252/8.
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4191609 | Mar., 1980 | Trokhan | 162/113.
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4208459 | Jun., 1980 | Becker et al. | 428/154.
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4239065 | Dec., 1980 | Trokhan | 139/383.
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4303471 | Dec., 1981 | Laursen | 162/158.
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4416950 | Nov., 1983 | Muller et al. | 428/537.
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4462981 | Jul., 1984 | Smith | 424/27.
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4481243 | Nov., 1984 | Allen | 428/154.
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4528239 | Jul., 1985 | Trokhan | 428/247.
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4569343 | Feb., 1986 | Kimura et al. | 128/155.
|
4569888 | Feb., 1986 | Muller et al. | 428/481.
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4690821 | Sep., 1987 | Smith et al. | 424/401.
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4732797 | Mar., 1988 | Johnson et al. | 428/74.
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|
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|
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4839395 | Jun., 1989 | Masamizu et al. | 521/56.
|
4885282 | Dec., 1989 | Thornfeldt | 514/552.
|
4904524 | Feb., 1990 | Yoh | 428/311.
|
4940513 | Jul., 1990 | Spendel | 162/112.
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4959059 | Sep., 1990 | Eilender et al. | 604/358.
|
4959125 | Sep., 1990 | Spendel | 162/158.
|
4960592 | Oct., 1990 | Hagen et al. | 424/537.
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5021405 | Jun., 1991 | Klimisch | 514/63.
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5026489 | Jun., 1991 | Snow et al. | 252/8.
|
5055216 | Oct., 1991 | Johnson | 252/91.
|
5057500 | Oct., 1991 | Thornfeldt | 514/53.
|
5059282 | Oct., 1991 | Ampulski et al. | 162/111.
|
5085920 | Feb., 1992 | Nohr et al. | 428/198.
|
5164046 | Nov., 1992 | Ampulski et al. | 162/111.
|
5174927 | Dec., 1992 | Honsa | 252/543.
|
5202400 | Apr., 1993 | Itoh et al. | 526/240.
|
5204110 | Apr., 1993 | Cartmell et al. | 424/443.
|
5215626 | Jun., 1993 | Ampulski et al. | 162/112.
|
5231087 | Jul., 1993 | Thornfeldt | 514/53.
|
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|
5268180 | Dec., 1993 | Morancais et al. | 424/450.
|
5306733 | Apr., 1994 | Adamski et al. | 521/63.
|
5331015 | Jul., 1994 | DesMarais et al. | 521/62.
|
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|
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|
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|
5412004 | May., 1995 | Tachibana et al. | 524/27.
|
Foreign Patent Documents |
2019557 | Dec., 1990 | CA.
| |
78006219 | May., 1973 | JP.
| |
61043606 | Aug., 1984 | JP.
| |
63-305872 | Jun., 1987 | JP.
| |
1311014 | Jun., 1988 | JP.
| |
6293614 | Jun., 1992 | JP.
| |
4-329913 | Nov., 1992 | JP.
| |
Primary Examiner: Venkat; Jyothsan
Attorney, Agent or Firm: Hersko; Bart S., Linman; E. Kelly, Rasser; Jacobus C.
Claims
What is claimed is:
1. A lotioned tissue paper having applied to at least one surface thereof,
in an amount of from about 0.1 to about 20% by weight of the dried tissue
paper, a lotion composition which is semi-solid or solid at 20.degree. C.
and which comprises:
(A) from about 5 to about 95% of a liquid polyol polyester emollient
comprising a polyhydric alcohol containing at least 4 hydroxyl groups
esterified with fatty acid or carboxylic acid having at least 2 carbon
atoms and up to 30 carbon atoms; and
(B) from about 5 to about 95% of an agent capable of immobilizing said
liquid polyol polyester emollient on the surface of tissue paper treated
with the lotion composition, said immobilizing agent having a melting
point of at least 35.degree. C.; and
(C) optionally from about 1 to about 50% of a hydrophilic surfactant having
an HLB value of at least about 4.
2. The lotioned paper according to claim 1 wherein at least about 85% of
the hydroxyl groups of said liquid polyol polyester are esterified.
3. The lotioned paper according to claim 1 wherein said liquid polyol
polyester comprises sucrose esterified with a mixture of fully
hydrogenated and partially hydrogenated cottonseed or soybean oil fatty
acid methyl esters, or mixtures thereof.
4. The lotioned paper according to claim 1 wherein said immobilizing agent
comprises a solid polyol polyester.
5. The lotioned paper according to claim 1 wherein said liquid polyol
polyester is selected from the group consisting of; liquid esters of
tricarballylic acids, liquid diesters of dicarboxylic acids, liquid
triglycerides of alpha-branched chain carboxylic acids, liquid ethers and
ether esters containing the neopentyl moiety, liquid fatty polyethers of
polyglycerol, liquid alkyl glycoside fatty acid polyesters, liquid
polyesters of two ether linked hydroxypolycarboxylic acids, liquid esters
of epoxide-extended polyols, and mixtures thereof.
6. The lotioned paper according to claim 3 wherein said liquid polyol
polyester emollient is selected from the group consisting of sucrose
polycottonate, sucrose polysoyate and mixtures thereof.
7. The lotioned paper according to claim 6 wherein said immobilizing agent
comprises a solid polyol polyester.
8. The lotioned paper according to claim 7 wherein said immobilizing agent
is sucrose polybehenate.
9. The lotioned paper according to claim 6 which has from about 0.1 to
about 20% by weight of said lotion composition applied to at least one
surface of the tissue paper.
10. The lotioned paper according to claim 6 further comprising a
polysiloxane or silicone wax emollient having a plastic or fluid
consistency at about 37.degree. C.
11. The lotioned paper according to claim 1 wherein said immobilizing agent
is sorbitan monostearate.
12. The lotioned paper according to claim 1 further comprising skin
soothing agents or anti-inflammatories.
13. The lotioned paper of claim 2 wherein the skin soothing agent is aloe
vera or panthenol.
Description
TECHNICAL FIELD
This application relates to lotion compositions for imparting a soft,
lubricious feel to tissue paper. This application further relates to
tissue paper treated with such lotion compositions.
BACKGROUND OF THE INVENTION
Cleansing the skin is a personal hygiene problem not always easily solved.
Of course, the common procedure of washing the skin with soap and water
works well, but at times may be either unavailable or inconvenient to use.
While soap and water could be used to clean the perianal region after
defecation for example, such a procedure would be extremely burdensome.
Dry tissue products are therefore the most commonly used post-defecation
anal cleansing product. These dry tissue products are usually referred to
as "toilet tissue" or "toilet paper."
The perianal skin is marked by the presence of fine folds and wrinkles
(sulci) and by hair follicles, both of which make the perianal region one
of the more difficult anatomical areas to cleanse. During defecation,
fecal matter is excreted through the anus and tends to accumulate in hard
to reach locations such as around the base of hairs and in the sulci of
the skin's surface. As the fecal matter dehydrates upon exposure to the
air, or upon contact with an absorbent cleansing implement such as tissue
paper, it adheres more tenaciously to the skin and hair, thus making
subsequent removal of the remaining dehydrated soil even more difficult.
Failure to remove fecal matter from the anal area can have a deleterious
effect on personal hygiene. The fecal matter remaining on the skin after
post-defecation cleansing has a high bacterial and viral content, is
malodorous and is generally dehydrated. These characteristics increase the
likelihood of perianal disorders and cause personal discomfort (e.g.,
itching, irritation, chafing, etc.). Further, the residual fecal matter
stains undergarments and causes unpleasant odors to emanate from the anal
region. Thus, the consequences of inadequate perianal cleansing are
clearly unattractive.
For those individuals suffering from anal disorders such as pruritis ani,
hemorrhoids, fissures, cryptiris, or the like, the importance of adequate
perianal cleansing takes on heightened significance. Perianal disorders
are usually characterized by openings in the skin through which the
bacteria and viruses in the residual fecal matter can readily enter. Those
people afflicted with anal disorders must, therefore, achieve a high
degree of perianal cleansing after defecation or risk the likely result
that their disorders will be aggravated by the bacteria and viruses
remaining on the skin.
At the same time anal disorder sufferers face more severe consequences from
insufficient post defecation cleaning, they have greater difficulty in
achieving a satisfactory level of soil removal. Anal disorders generally
render the perianal region extremely sensitive and attempts to remove
fecal matter from this region by wiping with even normal wiping pressure
causes pain and can further irritate the skin. Attempts to improve soil
removal by increasing the wiping pressure can result in intense pain.
Conversely, attempts to minimize discomfort by reducing the wiping
pressure result in an increased amount of residual fecal matter left on
the skin.
Conventional toilet tissue products used for anal cleaning are essentially
dry, high density tissue papers that rely exclusively on mechanical
processes to remove fecal matter from the perianal skin. These
conventional products are rubbed against the perianal skin, typically with
a pressure of about 1 psi (7 kilopascals) and basically scrape or abrade
the fecal matter from the skin. After the first few wipes, the upper
portion of the soil layer is removed because the wiping process is able to
overcome the soil-soil cohesive forces that exist within the fecal matter.
A cleavage is thereby created in the soil layer itself with the upper
portion of the fecal layer being removed and the lower portion of the soil
remaining adhered to the perianal skin.
Conventional tissue products are absorbent and with each successive wipe
the fecal matter becomes increasingly dehydrated, causing it to adhere
more tenaciously to the perianal skin and hair and making its removal
difficult in the extreme. Pressing the tissue forcefully against the
perianal skin will remove more of the fecal matter but is intensely
painful for people suffering from anal disorders and can excoriate even
normal perianal skin, potentially causing irritation, inflammation, pain,
bleeding, and infection.
Irritation and inflammation potentially caused by the use of tissue
products is not limited to toilet tissue. Facial tissue products used to
wipe and remove nasal discharges associated with colds, flu and allergies
can also cause such problems. In addition to difficulties in breathing,
seeing, and talking, an individual afflicted with these disorders
frequently has a sore and irritated nose. The nose, as well as the
surrounding tissue, e.g., upper lip area, are often red and inflamed to
the extent of becoming painful in extreme cases.
This irritation, inflammation and redness can have several causes. A prime
one is, of course, the sheer necessity of frequently blowing one's nose
into the tissue, and wiping the resultant nasal discharge from the nose
and surrounding area. The degree of irritation and inflammation caused by
such blowing and wiping is directly proportional to: (1) the surface
roughness of the tissue used; and (2) the number of times the nose and its
surrounding areas are in contact with the tissue. A tissue that is
relatively weak or relatively nonabsorbent requires a greater number of
contacts with the face than a stronger or more absorbent tissue that is
able to contain a greater quantity of nasal discharge.
There have been numerous previous attempts to reduce the abrasive effect of
toilet and facial tissues and to increase their softness impression. One
common approach is by mechanical processing. By using particular
processing steps during papermaking, toilet and facial tissue products can
be made that are softer and less irritating. Examples of tissue products
that are mechanically processed to be softer are shown in U.S. Pat. No.
4,300,981 (Carstens), issued Nov. 17, 1981, as well as the various patents
discussed in its specification.
Besides mechanical processing, others have applied emollients, salves,
cleansing agents, and the like to tissue products to enhance not only the
cleaning of the skin but also to reduce irritation and inflammation. This
reduction in irritation and inflammation is typically achieved through
either the lubricity of the substance applied to the tissue or through the
therapeutic action of the substance itself. This approach is illustrated
in U.S. Pat. No. 4,112,167 (Dake et al) issued Sep. 5, 1978, particularly
in regard to toilet tissues. See also in U.S. Pat. No. 3,896,807
(Buchalter), issued Jul. 29, 1975 and in U.S. Pat. No. 3,814,096 (Weiss et
al), issued Jun. 4, 1974 for other examples of this approach.
One substance that has been applied as a lotion to tissue products to
impart a soothing, lubricious feel is mineral oil. Mineral oil (also known
as liquid petrolatum) is a mixture of various liquid hydrocarbons obtained
by distilling the high-boiling (i.e., 300.degree.-390.degree. C.)
fractions in petroleum. Mineral oil is liquid at ambient temperatures,
e.g. 20.degree.-25.degree. C. As a result, mineral oil is relatively fluid
and mobile, even when applied to tissue products
Because mineral oil is fluid and mobile at ambient temperatures, it tends
not to remain localized on the surface of the tissue, but instead migrates
throughout. Accordingly, relatively high levels of mineral oil needs to be
applied to the tissue to provide the desired softness and lotion-like feel
benefits. These levels can be as high as about 22-25 wt. % of the tissue
product. This leads not only to increased costs for these lotioned tissue
products, but other detrimental effects as well.
One of these detrimental effects is a decrease in tensile strength of the
tissue product. As mineral oil migrates to the interior of the tissue, it
tends to act as a debonding agent, thus decreasing the tensile strength of
the product. This debonding effect becomes more pronounced as the level of
mineral oil applied is increased. Increasing the level of mineral oil
applied can also adversely affect the caliper of the tissue product.
Even without increasing its level, the tendency of mineral oil to migrate
once applied has other detrimental effects. For example, the applied
mineral oil can transfer to, into and through the packaging or wrapper
material for the lotioned toilet tissue product. This can create the need
for barrier-type packaging or wrapper films to avoid smearing or other
leakage of mineral oil from the tissue product.
Accordingly, it would be desirable to provide lotioned tissue products,
that: (1) have a desirable soothing, lubricious feel; (2) do not require
relatively high levels of mineral oil: (3) do not adversely affect the
tensile strength and caliper of the product; and (4) do not require
special wrapping or barrier materials for packaging.
It is yet a further object of the present invention to provide skin care
compositions that provide cleaning, and therapeutic or protective lotion
coating benefits.
SUMMARY OF THE INVENTION
The present invention relates to a lotion composition that is semisolid or
solid at ambient temperatures (i.e., at 20.degree. C.) and imparts a soft,
lubricious, lotion-like feel when applied to tissue paper. This lotion
composition comprises:
(A) from about 5 to about 95% of a liquid polyol emollient comprising a
polyhydric alcohol containing at least 4 hydroxyl groups esterified with
fatty acid or other organic radicals having at least 2 carbon atoms and up
to 30 carbon atoms; and
(B) from about 5 to about 95% of an agent capable of immobilizing said
liquid polyol polyester emollient on the surface of tissue paper treated
with the lotion composition, said immobilizing agent having a melting
point of at least 35.degree. C.; and
(C) optionally from about 1 to about 50% of a hydrophilic surfactant having
an HLB value of at least about 4.
The present invention further relates to lotioned tissue papers wherein the
lotion composition is applied to at least one surface thereof in an amount
of from about 0.1 to about 20% by weight of the dried tissue paper.
Lotioned tissue papers according to the present invention have a
desirable, lubricious, lotion-like feel. Because the emollient is
substantially immobilized on the surface of the tissue paper, less lotion
composition is needed to impart the desired soft, lotion-like feel. As a
result, the detrimental effects on the tensile strength and caliper of the
tissue caused by prior mineral oil-containing lotions can be avoided. In
addition, special barrier or wrapping materials are unnecessary in
packaging the lotioned tissue products of the present invention.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a schematic representation illustrating a preferred process for
applying the lotion composition of the present invention to tissue paper
webs.
FIG. 2 is a schematic representation illustrating an alternative process
for applying the lotion composition of the present invention to tissue
paper webs.
A. TISSUE PAPERS
The present invention is useful with tissue paper in general, including but
not limited to conventionally felt-pressed tissue paper; high bulk pattern
densified tissue paper; and high bulk, uncompacted tissue paper. The
tissue paper can be of a homogenous or multi-layered construction; and
tissue paper products made therefrom can be of a single-ply or multi-ply
construction. The tissue paper preferably has a basis weight of between
about 10 g/m.sup.2 and about 65 g/m.sup.2, and density of about 0.6 g/cc
or less. More preferably, the basis weight will be about 40 g/m.sup.2 or
less and the density will be about 0.3 g/cc or less. Most preferably, the
density will be between about 0.04 g/cc and about 0.2 g/cc. See Column 13,
lines 61-67, of U.S. Pat. No. 5,059,282 (Ampulski et al), issued Oct. 22,
1991, which describes how the density of tissue paper is measured. (Unless
otherwise specified, all amounts and weights relative to the paper are on
a dry basis.)
Conventionally pressed tissue paper and methods for making such paper are
well known in the art. Such paper is typically made by depositing a
papermaking furnish on a foraminous forming wire, often referred to in the
art as a Fourdrinier wire. Once the furnish is deposited on the forming
wire, it is referred to as a web. The web is dewatered by pressing the web
and drying at elevated temperature. The particular techniques and typical
equipment for making webs according to the process just described are well
known to those skilled in the art. In a typical process, a low consistency
pulp furnish is provided from a pressurized headbox. The headbox has an
opening for delivering a thin deposit of pulp furnish onto the Fourdrinier
wire to form a wet web. The web is then typically dewatered to a fiber
consistency of between about 7% and about 25% (total web weight basis) by
vacuum dewatering and further dried by pressing operations wherein the web
is subjected to pressure developed by opposing mechanical members, for
example, cylindrical rolls. The dewatered web is then further pressed and
dried by a steam drum apparatus known in the art as a Yankee dryer.
Pressure can be developed at the Yankee dryer by mechanical means such as
an opposing cylindrical drum pressing against the web. Multiple Yankee
dryer drums can be employed, whereby additional pressing is optionally
incurred between the drums. The tissue paper structures that are formed
are referred to hereafter as conventional, pressed, tissue paper
structures. Such sheets are considered to be compacted since the entire
web is subjected to substantial mechanical compressional forces while the
fibers are moist and are then dried while in a compressed state.
Pattern densified tissue paper is characterized by having a relatively high
bulk field of relatively low fiber density and an array of densified zones
of relatively high fiber density. The high bulk field is alternatively
characterized as a field of pillow regions. The densified zones are
alternatively referred to as knuckle regions. The densified zones can be
discretely spaced within the high bulk field or can be interconnected,
either fully or partially, within the high bulk field. The patterns can be
formed in a nonornamental configuration or can be formed so as to provide
an ornamental design(s) in the tissue paper. Preferred processes for
making pattern densified tissue webs are disclosed in U.S. Pat. No.
3,301,746 (Sanford et al), issued Jan. 31, 1967; U.S. Pat. No. 3,974,025
(Ayers), issued Aug. 10, 1976; and U.S. Pat. No. 4,191,609 (Trokhan)
issued Mar. 4, 1980; and U.S. Pat. No. 4,637,859 (Trokhan) issued Jan. 20,
1987; all of which are incorporated by reference.
In general, pattern densified webs are preferably prepared by depositing a
papermaking furnish on a foraminous forming wire such as a Fourdrinier
wire to form a wet web and then juxtaposing the web against an array of
supports. The web is pressed against the array of supports, thereby
resulting in densified zones in the web at the locations geographically
corresponding to the points of contact between the array of supports and
the wet web. The remainder of the web not compressed during this operation
is referred to as the high bulk field. This high bulk field can be further
dedensified by application of fluid pressure, such as with a vacuum type
device or a blow-through dryer, or by mechanically pressing the web
against the array of supports. The web is dewatered, and optionally
predried, in such a manner so as to substantially avoid compression of the
high bulk field. This is preferably accomplished by fluid pressure, such
as with a vacuum type device or blow-through dryer, or alternately by
mechanically pressing the web against an array of supports wherein the
high bulk field is not compressed. The operations of dewatering, optional
predrying and formation of the densified zones can be integrated or
partially integrated to reduce the total number of processing steps
performed. Subsequent to formation of the densified zones, dewatering, and
optional predrying, the web is dried to completion, preferably still
avoiding mechanical pressing. Preferably, from about 8% to about 55% of
the tissue paper surface comprises densified knuckles having a relative
density of at least 125% of the density of the high bulk field.
The array of supports is preferably an imprinting carrier fabric having a
patterned displacement of knuckles that operate as the array of supports
that facilitate the formation of the densified zones upon application of
pressure. The pattern of knuckles constitutes the array of supports
previously referred to. Suitable imprinting carrier fabrics are disclosed
in U.S. Pat. No. 3,301,746 (Sanford et al), issued Jan. 31, 1967; U.S.
Pat. No. 3,821,068 (Salvucci et al), issued May 21, 1974; U.S. Pat. No.
3,974,025 (Ayers), issued Aug. 10, 1976; U.S. Pat. No. 3,573,164
(Friedberg et al.), issued Mar. 30, 1971; U.S. Pat. No. 3,473,576
(Amneus), issued Oct. 21, 1969; U.S. Pat. No. 4,239,065 (Trokhan), issued
Dec. 16, 1980; and U.S. Pat. No. 4,528,239 (Trokhan), issued Jul. 9, 1985,
all of which are incorporated by reference.
Preferably, the furnish is first formed into a wet web on a foraminous
forming carrier, such as a Fourdrinier wire. The web is dewatered and
transferred to an imprinting fabric. The furnish can alternately be
initially deposited on a foraminous supporting carrier that also operates
as an imprinting fabric. Once formed, the wet web is dewatered and,
preferably, thermally predried to a selected fiber consistency from about
40% to about 80%. Dewatering is preferably performed with suction boxes or
other vacuum devices or with blow-through dryers. The knuckle imprint of
the imprinting fabric is impressed in the web as discussed above, prior to
drying the web to completion. One method for accomplishing this is through
application of mechanical pressure. This can be done, for example, by
pressing a nip roll that supports the imprinting fabric against the face
of a drying drum, such as a Yankee dryer, wherein the web is disposed
between the nip roll and drying drum. Also, preferably, the web is molded
against the imprinting fabric prior to completion of drying by application
of fluid pressure with a vacuum device such as a suction box, or with a
blow-through dryer. Fluid pressure can be applied to induce impression of
densified zones during initial dewatering, in a separate, subsequent
process stage, or a combination thereof.
Uncompacted, nonpattern-densified tissue paper structures are described in
U.S. Pat. No. 3,812,000 (Salvucci et al), issued May 21, 1974 and U.S.
Pat. No. 4,208,459 (Becker et al), issued Jun. 17, 1980, both of which are
incorporated by reference. In general, uncompacted, nonpattern-densified
tissue paper structures are prepared by depositing a papermaking furnish
on a foraminous forming wire such as a Fourdrinier wire to form a wet web,
draining the web and removing additional water without mechanical
compression until the web has a fiber consistency of at least about 80%,
and creping the web. Water is removed from the web by vacuum dewatering
and thermal drying. The resulting structure is a soft but weak, high bulk
sheet of relatively uncompacted fibers. Bonding material is preferably
applied to portions of the web prior to creping.
Compacted non-pattern-densified tissue structures are commonly known in the
art as conventional tissue structures. In general, compacted,
non-pattern-densified tissue paper structures are prepared by depositing a
papermaking furnish on a foraminous wire such as a Fourdrinier wire to
form a wet web, draining the web and removing additional water with the
aid of a uniform mechanical compaction (pressing) until the web has a
consistency of 25-50%, transferring the web to a thermal dryer such as a
Yankee and creping the web. Overall, water is removed from the web by
vacuum, mechanical pressing and thermal means. The resulting structure is
strong and generally of singular density, but very low in bulk, absorbency
and softness.
The papermaking fibers utilized for the present invention will normally
include fibers derived from wood pulp. Other cellulosic fibrous pulp
fibers, such as cotton linters, bagasse, etc., can be utilized and are
intended to be within the scope of this invention. Synthetic fibers, such
as rayon, polyethylene and polypropylene fibers, can also be utilized in
combination with natural cellulosic fibers. One exemplary polyethylene
fiber that can be utilized is Pulpex.RTM., available from Hercules, Inc.
(Wilmington, Del.).
Applicable wood pulps include chemical pulps, such as Kraft, sulfite, and
sulfate pulps, as well as mechanical pulps including, for example,
groundwood, thermomechanical pulp and chemically modified thermomechanical
pulp. Chemical pulps, however, are preferred since they impart a superior
tactile sense of softness to tissue sheets made therefrom. Pulps derived
from both deciduous trees (hereafter, also referred to as "hardwood") and
coniferous trees (hereafter, also referred to as "softwood") can be
utilized. Also useful in the present invention are fibers derived from
recycled paper, which can contain any or all of the above categories as
well as other non-fibrous materials such as fillers and adhesives used to
facilitate the original papermaking.
In addition to papermaking fibers, the papermaking furnish used to make
tissue paper structures can have other components or materials added
thereto as can be or later become known in the art. The types of additives
desirable will be dependent upon the particular end use of the tissue
sheet contemplated. For example, in products such as toilet paper, paper
towels, facial tissues and other similar products, high wet strength is a
desirable attribute. Thus, it is often desirable to add to the papermaking
furnish chemical substances known in the art as "wet strength" resins.
A general dissertation on the types of wet strength resins utilized in the
paper art can be found in TAPPI monograph series No. 29, Wet Strength in
Paper and Paperboard, Technical Association of the Pulp and Paper Industry
(New York, 1965). The most useful wet strength resins have generally been
cationic in character. For permanent wet strength generation,
polyamide-epichlorohydrin resins are cationic wet strength resins have
been found to be of particular utility. Suitable types of such resins are
described in U.S. Pat. No. 3,700,623 (Keim), issued Oct. 24, 1972, and
U.S. Pat. No. 3,772,076 (Keim), issued Nov. 13, 1973, both of which are
incorporated by reference. One commercial source of a useful
polyamide-epichlorohydrin resin is Hercules, Inc. of Wilmington, Del.,
which markets such resins under the mark Kymene.RTM. 557H.
Polyacrylamide resins have also been found to be of utility as wet strength
resins. These resins are described in U.S. Pat. Nos. 3,556,932 (Coscia et
al), issued Jan. 19, 1971, and 3,556,933 (Williams et al), issued Jan. 19,
1971, both of which are incorporated herein by reference. One commercial
source of polyacrylamide resins is American Cyanamid Co. of Stamford,
Conn., which markets one such resin under the mark Parez.RTM. 631 NC.
Still other water-soluble cationic resins finding utility in this invention
are urea formaldehyde and melamine formaldehyde resins. The more common
functional groups of these polyfunctional resins are nitrogen containing
groups such as amino groups and methylol groups attached to nitrogen.
Polyethylenimine type resins can also find utility in the present
invention. In addition, temporary wet strength resins such as Caldas 10
(manufactured by Japan Carlit) and CoBond 1000 (manufactured by National
Starch and Chemical Company) can be used in the present invention. It is
to be understood that the addition of chemical compounds such as the wet
strength and temporary wet strength resins discussed above to the pulp
furnish is optional and is not necessary for the practice of the present
invention.
In addition to wet strength additives, it can also be desirable to include
in the papermaking fibers certain dry strength and lint control additives
known in the art. In this regard, starch binders have been found to be
particularly suitable. In addition to reducing linting of the finished
tissue paper product, low levels of starch binders also impart a modest
improvement in the dry tensile strength without imparting stiffness that
could result from the addition of high levels of starch. Typically the
starch binder is included in an amount such that it is retained at a level
of from about 0.01 to about 2%, preferably from about 0.1 to about 1%, by
weight of the tissue paper.
In general, suitable starch binders for the present invention are
characterized by water solubility and hydrophilicity. Although it is not
intended to limit the scope of suitable starch binders, representative
starch materials include corn starch and potato starch, with waxy corn
starch known industrially as amioca starch being particularly preferred.
Amioca starch differs from common corn starch in that it is entirely
amylopectin, whereas common corn starch contains both amylopectin and
amylose. Various unique characteristics of amioca starch are further
described in "Amioca--The Starch From Waxy Corn", H. H. Schopmeyer, Food
Industries, December 1945, pp. 106-108 (Vol. pp. 1476-1478).
The starch binder can be in granular or dispersed form, the granular form
being especially preferred. The starch binder is preferably sufficiently
cooked to induce swelling of the granules. More preferably, the starch
granules are swollen, as by cooking, to a point just prior to dispersion
of the starch granule. Such highly swollen starch granules shall be
referred to as being "fully cooked." The conditions for dispersion in
general can vary depending upon the size of the starch granules, the
degree of crystallinity of the granules, and the amount of amylose
present. Fully cooked amioca starch, for example, can be prepared by
heating an aqueous slurry of about 4% consistency of starch granules at
about 190.degree. F. (about 88.degree. C.) for between about 30 and about
40 minutes. Other exemplary starch binders that can be used include
modified cationic starches such as those modified to have nitrogen
containing groups, including amino groups and methylol groups attached to
nitrogen, available from National Starch and Chemical Company,
(Bridgewater, N.J.), that have previously been used as pulp furnish
additives to increase wet and/or dry strength.
B. Lotion Composition
The lotion compositions of the present invention are solid, or more often
semisolid, at 20.degree. C., i.e. at ambient temperatures. By "semisolid"
is meant that the lotion composition has a rheology typical of
pseudoplastic or plastic fluids, When no shear is applied, the lotion
compositions can have the appearance of a semi-solid but can be made to
flow as the shear rate is increased. This is due to the fact that, while
the lotion composition contains primarily solid components, it also
includes some minor liquid components.
By being solid or semisolid at ambient temperatures, these lotion
compositions do not have a tendency to flow and migrate into the interior
of the tissue web to which they are applied. This means less lotion
composition is required for imparting softness and lotion-like feel
benefits. It also means there is less chance for debonding of the tissue
paper that can potentially lead to decreases in tensile strength.
When applied to tissue paper, the lotion compositions of the present
invention impart a soft, lubricious, lotion like feel to the user of the
paper. This particular feel has also been characterized as "silky",
"slick", "smooth", etc. Such a lubricious, lotion-like feel is
particularly beneficial for those having more sensitive skin due to
chronic conditions such as skin dryness or hemorrhoids, or due to more
transient conditions such as colds or allergies.
The lotion compositions of the present invention comprise: (1) a liquid
polyol polyester(s) emollient; (2) an immobilizing agent for the liquid
polyol polyester(s) emollient; (3) optionally a hydrophilic surfactant(s);
and (4) other optional components.
Polyol Polyesters
By "polyol" is meant a polyhydric alcohol containing at least 4, preferably
from 4 to 12, and, most preferably from 6 to 8, hydroxyl groups. Polyols
include monosaccharides, disaccharides and trisaccharides, sugar alcohols
other sugar derivatives (e.g., alkyl glycosides), polyglycerols (e.g.,
diglycerol and triglycerol), pentaerythritol, and polyvinyl alcohols.
Preferred polyols include xylose, arabinose, ribose, xylitol, erythritol,
glucose, methyl glucoside, mannose, galactose, fructose, sorbitol,
maltose, lactose, sucrose, raffinose, and maltotriose. Sucrose is an
especially preferred polyol.
By "polyol polyester" is meant a polyol having at least 4 ester groups. It
is not necessary that all of the hydroxyl groups of the polyol be
esterified, however disaccharides polyesters should have no more than 3,
and more preferably no more than 2 unesterified hydroxyl groups.
Typically, substantially all (e.g., at least about 85%) of the hydroxyl
groups of the polyol are esterified. In the case of sucrose polyesters,
typically from about 7 to 8 of the hydroxyl groups of the polyol are
esterified.
By "liquid polyol polyester" is meant a polyol polyester from the
hereinafter described groups having a fluid consistency at or below about
37.degree. C. By "solid polyol polyester" is meant a polyol polyester from
the hereinafter described groups having a plastic or solid consistency at
or above about 37.degree. C. As hereinafter described, liquid polyol
polyesters and solid polyol polyesters may be successfully employed as
emollients and immobilizing agents, respectively, in lotion compositions
of the present invention. In some cases, solid polyol polyesters may also
provide some emolliency functionality.
Fatty acids and/or other organic radicals having at least 2 carbon atoms
and up to 30 carbon atoms can be used to esterify the polyol. Typically
they contain from 8-22 carbon atoms, and more typically at least 12-16
carbon atoms. The acid radicals can be saturated or Unsaturated, including
positional or geometrical isomers, e.g. cis- or trans-isomers, straight
chain or branched chain aliphatic or aromatic, and can be the same for all
ester groups, or can be mixtures of different acid radicals. Cyclic
aliphatics such as cyclohexane carboxylic and polymeric ester-forming
radicals such as polyacrylic and dimer fatty acid can also be used to
esterify the polyol.
Liquid polyol polyesters and nondigestible oils have a complete melting
point at or below about 37.degree. C. Suitable liquid nondigestible edible
oils for use herein include liquid polyol polyesters (see Mattson &
Volpenhein, U.S. Pat. No. 3,600,186 issued Aug. 17, 1971, Jandacek; U.S.
Pat. No. 4,005,195; Issued Jan. 25, 1977); liquid esters of tricarballylic
acids (see Hamm; U.S. Pat. No. 4,508,746; Issued Apr. 2, 1985); liquid
diesters of dicarboxylic acids such as derivatives of malonic and succinic
acid (see Fulcher, U.S. Pat. No. 4,582,927; Issued Apr. 15, 1986); liquid
triglycerides of alpha-branched chain carboxylic acids (see Whyte; U.S.
Pat. No. 3,579,548; Issued May 18, 1971); liquid ethers and ether esters
containing the neopentyl moiety (see Minich; U.S. Pat. No. 2,962,419;
Issued Nov. 9, 1960); liquid fatty polyethers of polyglycerol (See Hunter
et al; U.S. Pat. No. 3,932,532; Issued Jan. 13, 1976); liquid alkyl
glycoside fatty acid polyesters (see Meyer et al; U.S. Pat. No. 4,840,815;
Issued Jun. 20, 1989); liquid polyesters of two ether linked
hydroxypolycarboxylic acids (e.g., citric or isocitric acid) (see Huhn et
al; U.S. Pat. No. 4,888,195; Issued Dec. 19, 1988); and liquid esters of
epoxide-extended polyols (see White et al; U.S. Pat. No. 4,861,613; Issued
Aug. 29, 1989).
Preferred liquid nondigestible oils are sugar polyesters, sugar alcohol
polyesters, and mixtures thereof, preferably esterified with fatty acids
containing from 8 to 22 carbon atoms, and most preferably from fatty acids
having 8 to 18 carbon atoms. Those which have minimal or no solids at body
temperatures (i.e., 98.6.degree. F., 37.degree. C.) usually contain ester
groups having a high proportion of C.sub.12 or lower fatty acid radicals
or else a high proportion of C.sub.18 or higher unsaturated fatty acid
radicals. Preferred unsaturated fatty acids in such liquid polyol
polyesters are oleic acid, linoleic acid, and mixtures thereof.
Nondigestible polyol polyester hardstock or solid materials suitable for
use herein can be selected from solid sugar polyesters, solid sugar
alcohol polyesters and mixtures thereof, and contain ester groups, e.g.
generally 5 to 8 ester groups, which consist essentially of long chain
saturated fatty acid radicals. Suitable saturated fatty acid radicals
contain at least 14, preferably from 14 to 26, most preferably from 16 to
22, carbon atoms. The long chain saturated fatty acid radicals can be used
singly or in mixtures with each other. In addition, straight chain (i.e.
normal) fatty acid radicals are typical for the long chain saturated fatty
acid radicals.
Certain intermediate melting polyol fatty acid polyesters have been
developed that have a specific rheology that defines their physical
properties, i.e., their melting points, viscosity, shear rates and shear
viscosities and crystal size and shape are also useful. (See Bernhardt;
European Patent Application Nos. 236,288 and 233,856; Published Sep. 9,
and Aug. 26, 1987, respectively.) These intermediate melting polyol
polyesters are viscous and have a high liquid/solid stability at body
temperature that makes them good for coating skin. An example of such
intermediate melting polyol polyesters are those obtained by substantially
completely esterifying sucrose with a 55:45 mixture of fully hydrogenated
and partially hydrogenated cottonseed or soybean oil fatty acid methyl
esters.
Preferred liquid polyol polyesters comprise sucrose polyesters. Especially
preferred liquid polyol polyesters comprise sucrose esterified with a
mixture of fully hydrogenated and partially hydrogenated cottonseed or
soybean oil fatty acid methyl esters, or mixtures thereof, hereinafter
referred to as sucrose polycottonate and sucrose polysoyate, respectively.
Blends of completely liquid polyol polyesters with completely solid polyol
polyester hardstocks, preferably esterified with C.sub.10 -C.sub.22
saturated fatty acids (e.g. sucrose octastearate), can be solid at room
temperature. (See, for example, Jandacek; U.S. Pat. No. 4,005,195; and
Jandacek/Mattson; U.S. Pat. No. 4,005,196; both issued Jan. 25, 1977, and
both of which are incorporated herein by reference.)
Liquid or solid polyol polyesters can be prepared by a variety of methods
known to those skilled in the art. These methods include:
transesterification of the polyol (i.e. sugar or sugar alcohol) with
methyl, ethyl or glycerol esters containing the desired acid radicals
using a variety of catalysts; acylation of the polyol with an acid
chloride; acylation of the polyol with an acid anhydride; and acylation of
the polyol with the desired acid, per se. (See, for example, U.S. Pat.
Nos. 2,831,854, 3,600,186, 3,963,699, 4,517,360 and 4,518,772, all of
which are incorporated by reference. These patents all disclose suitable
methods for preparing polyol polyesters.)
When making mixtures of liquid and solid nondigestible and nonabsorbable
materials, the nondigestible particles can be dispersed as discrete,
unaggregated entities in the liquid nondigestible oil. However, these
nondigestible particles can also cluster together to form much larger
aggregates which are dispersed in the liquid nondigestible oil. This is
particularly true of those nondigestible particles that are platelet-like
in form. Aggregates of platelet-like nondigestible particles typically
assume a spherulitic shape that is porous in character and thus capable of
entrapping significant amounts of liquid nondigestible oil.
Solid nondigestible particles can be used alone or dispersed in the
nondigestible liquid oil component.
Diversely Esterified Polyol Polyesters
"Diversely esterified polyol polyesters" contain two basic types of ester
groups: (a) groups formed from long chain saturated fatty acids radicals,
and (b) groups formed from acid radicals which are "dissimilar" to these
long chain saturated fatty acid radicals.
Suitable long chain saturated fatty acid radicals contain from 20 to 30,
most preferably 22-26, carbon atoms. The long chain saturated fatty acid
radicals can be used singly, or in mixtures with each other, in all
proportions. Usually, straight chain (i.e. normal) fatty acid radicals are
used.
The dissimilar radicals can comprise C.sub.12 or higher unsaturated fatty
acid radicals or C.sub.2 -C.sub.12 saturated fatty acid radicals or
mixtures thereof, or can be fatty-fatty acids aromatic acid radicals, or
ultra-long chain fatty acids or various branched cyclic or substituted
acid radicals.
Preferred "dissimilar" acid radicals comprises long chain unsaturated fatty
acid radicals, containing at least 12, preferably from 12 to 26, more
preferably from 18 to 22 carbon atoms and short chain saturated fatty acid
radicals having from 2 to 12 and preferably from 6 to 12 carbon atoms and
mixtures thereof.
A more preferred solid polyol polyester comprises a sucrose octaester
wherein, on average, 7 of the 8 sucrose hydroxyl groups have been
esterified with behenic acid and the remaining group has been esterified
with a short chain fatty acid having from 6 to 12 carbon atoms. In an
especially preferred embodiment, the short chain fatty acid comprises
oleic acid. Said solid sucrose polyesters wherein about 7 of the sucrose
hydroxl groups have been esterified with behenic acid are hereinafter
referred to as sucrose behenate.
Fatty-fatty acid radicals are a fatty acid radical having at least one
hydroxyl group that is itself esterified with another fatty acid or other
organic acid. Ricinoleic acid is a preferred hydroxy-fatty acid. Sources
of hydroxy-fatty acids include hydrogenated castor oil, strophanthus seed
oils, calendula officinalis seed oils, hydrogenated strophanthus seed oils
and hydrogenated calendula officinalis seed oils, cardamine impatiens seed
oils, kamala oils, mallotus discolor oils, and mallotus claoxyloides oils.
Hydroxy fatty acids can also be synthetically prepared by oxidative
hydroxylation of unsaturated fatty acids using oxidizing agents such as
potassium permanganate, osmium tetroxide, and peracids such as peracetic
acid. Using this method, 9, 10-dihydroxy-octadecanoic acid can be made
from oleic acid, and 9, 10, 12, 13-tetrahydroxy-octadecanoic acid can be
made from linoleic acid. Another way to prepare hydroxy fatty acids, such
as 10-hydroxy-12-cis-octadecenoic and 10-hydroxy-12 cis,
15-cis-octadecactanoic acids, synthetically is by conversion of fatty
acids such as linoleic and linolenic via microorganisms such as Nocardia
Cholesteroljim.
The same fatty acids sources used for esterification of the polyols can be
used for esterification of the hydroxyl group of the hydroxy-fatty acid
radical. These include aromatic acids such as benzoic or toluic; branched
chain radicals such as isobutyric, neoctanoic or methyl stearic acids;
ultra-long chain saturated or unsaturated fatty acid radicals, such as
triconsanoic or triconsenoic; cyclic aliphatics such as cyclohexane
carboxylic; and polymeric ester-forming radicals such as polyacrylic and
dimer fatty acid.
Aromatic acid radicals can also be used as a dissimilar ester group. A wide
variety of aromatic compounds including benzoic compounds such as benzoic
or toluic acid; amino benzoic compounds such as amino benzoic and
aminomethyl benzoic acids; hydroxybenzoic compounds such as
hydroxybenzoic, vanillic and salicylic acids; methoxybenzoic compounds
such as anisic acid; acetoxyphenylacetic compounds such as acetylmandelic
acid; and halobenzoic compounds such as chlorobenzoic, dichlorobenzoic,
and fluorobenzoic acids; acetyl benzoic, cumic, phenylbenzoic, and
nicotinic; and polycyclic aromatic radicals including fluorene carboxylic
can be used singly, or in mixtures with each other, in all proportions.
Various other ester-forming radicals can also serve as those which form the
dissimilar ester groups of the diversely esterified polyol polyester
particles used herein. Such other radicals can be branched alkyl chain;
ultra-long chain saturated or unsaturated radicals; cyclic aliphatic
radicals including cyclobutane carboxylic, cyclopentane carboxylic,
cyclohexane carboxylic, cyclohexane acetic, and hydroxycyclic such as
ascorbic; polycyclic aliphatic such as abietic acid; polymeric
ester-forming radicals such as polyacrylic and dimer fatty acid; and alkyl
chain radicals containing halogen amino or aryl groups.
The diversely esterified polyol polyesters can be prepared by esterifying
the desired polyol with the requisite type of ester-forming radicals by
the methods described for making polyol polyesters. When using a methyl
ester route to prepare these diversely esterified solid polyol polyesters
having mixed dissimilar acid radicals and long chain saturated fatty acid
radicals, the octaester of one of the types of acids (e.g., dissimilar
acids, or long chain saturated fatty acids) can be prepared first,
followed by partial interesterification of this initial reaction product
with the methyl ester of the other type of acid.
Polyol Polyester Polymers
Other solid nondigestible polyol polyesters comprise polyol polyester
polymers. Polyol polyester polymers are formed by polymerizing a polyol
polyester monomer to provide a molecule having at least two separate
esterified polyol moieties linked by covalent bonds between the fatty acid
radicals. For example, two sucrose octabehenate monomers could be
cross-linked between fatty acids to form a polymer. Repeating units of
such polyol polyester polymers can be the same or different such that the
generic term "polymer" in this context includes the specific term
"copolymer". The number of repeating monomer (or co-monomer) units which
make up such polyol polyester polymers can range from about 2 to 20,
preferably from about 2 to 12. Depending on the method of preparing them,
the polyol polyester polymers are frequently oligomers containing from 2
to 4 monomeric units, i.e., dimers, trimers, or tetramers.
The most preferred polyol polyester polymers are sucrose polyester polymers
having a number average molecular weight of from about 4000 to about
60,000, preferably from about 4000 to about 36,000, more preferably from
about 5000 to about 12,000.
One way to prepare solid polyol polyester polymers is by polymerizing
polyol polyesters using well known methods, including, but not limited to,
photochemical reactions and reactions with transition metal ions, heat or
free radical initiators such as di-tert-butyl peroxide.
Alternatively, polyol polyester polymers can be prepared directly by
esterifying and/or interesterifying the polyol material with polybasic
polymerized fatty acids or their derivatives. For example, the polyol
polyester polymers could be prepared by reacting the acid chlorides or
acid anhydrides of the desired polymer acids with sucrose, preferably
using a sequential esterification process. Polyol polyester polymers can
also be prepared by reacting methyl esters of the desired polymer acids
with sucrose in the presence of a fatty acid soap and a basic catalyst
such as potassium carbonate.
Common examples of polymerizable acids are those containing two or more
double bonds (polyunsaturated acids) such as the linoleic acid, linolenic
and eleostearic acids. parinaric acid, eicosadienoic acid,
eicosatetraenoic acid, arachidonic acid, 5,13-docosadienoic acid and
clupanodonic acid. Monounsaturated fatty acids, such as oleic, elaidic and
erucic acids, can also be used in preparing suitable long chain fatty acid
dimers which in turn can then be used to form the solid polyol polyester
polymers. Preferred polybasic polymerized fatty acids and fatty acid
derivatives for use in preparing polymer-containing polyol polyesters
include dibasic acids produced by dimerization of the fatty acids or fatty
acid lower esters derived from polyunsaturated vegetable oils such as
soybean oil or cottonseed oil or from animal fats such as tallow.
All of the foregoing types of polybasic polymerized fatty acids may
themselves be made by a variety of methods known to those skilled in the
art. (See Lutton; U.S. Pat. No. 3,353,967; Issued Nov. 21, 1967, Goebel;
U.S. Pat. No. 2,482,761; Issued Sep. 27, 1949, Harrison et al; U.S. Pat.
No. 2,731,481; Issued Jan. 17, 1956 and Barrett et al; U.S. Pat. No.
2,793,219; Issued May 21, 1957, all of which are incorporated herein by
reference.)
1. Emollient
A key active ingredient in lotion compositions of this invention is a
liquid polyol polyester emollient(s) as hereinbefore described.
Optionally, other emollients may also be incorporated in the liquid
formulation in additiuon to the liquid polyol polyester emollient(s).
Suitable additional emollients are hereinafter described. As used herein,
an emollient is a material that softens, soothes, supples, coats,
lubricates, moisturizes, or cleanses the skin. An emollient typically
accomplishes several of these objectives such as soothing, moisturizing,
and lubricating the skin. For the purposes of the present invention, these
emollients have either a plastic or fluid consistency at 20.degree. C.,
i.e., at ambient temperatures. This particular emollient consistency
allows the lotion composition to impart a soft, lubricious, lotion-like
feel.
The emollients useful in the present invention are also substantially free
of water. By "substantially free of water" is meant that water is not
intentionally added to the emollient. Addition of water to the emollient
is not necessary in preparing or using the lotion compositions of the
present invention and could require an additional drying step. However,
minor or trace quantities of water in the emollient that are picked up as
a result of, for example, ambient humidity can be tolerated without
adverse effect. Typically, the emollients used in the present invention
contain about 5% or less water, preferably about 1% or less water, most
preferably about 0.5% or less water.
Additional emollients useful in the present invention can be
petroleum-based, fatty acid ester type, alkyl ethoxylate type, fatty acid
ester ethoxylates, fatty alcohol type, polysiloxane type, or mixtures of
these emollients. Suitable petroleum-based emollients include those
hydrocarbons, or mixtures of hydrocarbons, having chain lengths of from 16
to 32 carbon atoms. Petroleum based hydrocarbons having these chain
lengths include mineral oil (also known as "liquid petrolatum") and
petrolatum (also known as "mineral wax," "petroleum jelly" and "mineral
jelly"). Mineral oil usually refers to less viscous mixtures of
hydrocarbons having from 16 to 20 carbon atoms. Petrolatum usually refers
to more viscous mixtures of hydrocarbons having from 16 to 32 carbon
atoms. Petrolatum and mineral oil are particularly preferred emollients
for lotion compositions of the present invention.
Suitable fatty acid ester type emollients include those derived from
C.sub.12 -C.sub.28 fatty acids, preferably C.sub.16 -C.sub.22 saturated
fatty acids, and short chain (C.sub.1 -C.sub.8, preferably C.sub.1
-C.sub.3) monohydric alcohols. Representative examples of such esters
include methyl palmirate, methyl stearate, isopropyl laurate, isopropyl
myristate, isopropyl palmirate, ethylhexyl palmirate and mixtures thereof.
Suitable fatty acid ester emollients can also be derived from esters of
longer chain fatty alcohols (C.sub.12 -C.sub.28, preferably C.sub.12
-C.sub.16) and shorter chain fatty acids e.g., lactic acid, such as lauryl
lactate and cetyl lactate.
Suitable alkyl ethoxylate type emollients include C.sub.12 -C.sub.22 fatty
alcohol ethoxylates having an average degree of ethoxylation of from about
2 to about 30. Preferably, the fatty alcohol ethoxylate emollient is
selected from the group consisting of lauryl, cetyl, and stearyl
ethoxylates, and mixtures thereof, having an average degree of
ethoxylation ranging from about 2 to about 23. Representative examples of
such alkyl ethoxylates include laureth-3 (a lauryl ethoxylate having an
average degree of ethoxylation of 3), laureth-23 (a lauryl ethoxylate
having an average degree of ethoxylation of 23), ceteth-10 (acetyl alcohol
ethoxylate having an average degree of ethoxylation of 10) and steareth-10
(a stearyl alcohol ethoxylate having an average degree of ethoxylation of
10). These alkyl ethoxylate emollients are typically used in combination
with the petroleum-based emollients, such as petrolatum, at a weight ratio
of alkyl ethoxylate emollient to petroleum-based emollient of from about
1:1 to about 1:5, preferably from about 1:2 to about 1:4.
Suitable fatty alcohol type emollients include C.sub.12 -C.sub.22 fatty
alcohols, preferably C.sub.16 -C.sub.18 fatty alcohols. Representative
examples include cetyl alcohol and stearyl alcohol, and mixtures thereof.
These fatty alcohol emollients are typically used in combination with the
petroleum-based emollients, such as petrolatum, at a weight ratio of fatty
alcohol emollient to petroleum-based emollient of from about 1:1 to about
1:5, preferably from about 1:1 to about 1:2.
Other suitable types of emollients for use in the present invention include
polysiloxane compounds. In general suitable polysiloxane materials for use
in the present invention include those having monomeric siloxane units of
the following structure:
##STR1##
wherein, R.sub.1 and R.sub.2, for each independent siloxane monomeric unit
can each independently be hydrogen or any alkyl, aryl, alkenyl, alkaryl,
arakyl, cycloalkyl, halogenated hydrocarbon, or other radical. Any of such
radicals can be substituted or unsubstituted. R.sub.1 and R.sub.2 radicals
of any particular monomeric unit may differ from the corresponding
functionalities of the next adjoining monomeric unit. Additionally, the
polysiloxane can be either a straight chain, a branched chain or have a
cyclic structure. The radicals R.sub.1 and R.sub.2 can additionally
independently be other silaceous functionalities such as, but not limited
to siloxanes, polysiloxanes, silanes, and polysilanes. The radicals
R.sub.1 and R.sub.2 may contain any of a variety of organic
functionalities including, for example, alcohol, carboxylic acid, phenyl,
and amine functionalities.
Exemplary alkyl radicals are methyl, ethyl, propyl, butyl, pentyl, hexyl,
octyl, decyl, octadecyl, and the like. Exemplary alkenyl radicals are
vinyl, allyl, and the like. Exemplary aryl radicals are phenyl, diphenyl,
naphthyl, and the like. Exemplary alkaryl radicals are toyl, xylyl,
ethylphenyl, and the like. Exemplary aralkyl radicals are benzyl,
alpha-phenylethyl, beta-phenylethyl, alpha-phenylbutyl, and the like.
Exemplary cycloalkyl radicals are cyclobutyl, cyclopentyl, cyclohexyl, and
the like. Exemplary halogenated hydrocarbon radicals are chloromethyl,
bromoethyl, tetrafluorethyl, fluorethyl, trifluorethyl, trifluorotloyl,
hexafluoroxylyl, and the like.
Viscosity of polysiloxanes useful may vary as widely as the viscosity of
polysiloxanes in general vary, so long as the polysiloxane is flowable or
can be made to be flowable for application to the tissue. This includes,
but is not limited to, viscosity as low as 5 centistokes (at 37.degree. C.
as measured by a glass viscometer) to about 20,000,000 centistokes.
Preferably the polysiloxanes have a viscosity at 37.degree. C. ranging
from about 5 to about 5,000 centistokes, more preferably from about 5 to
about 2,000 centistokes, most preferably from about 100 to about 1000
centistokes. High viscosity polysiloxanes which themselves are resistant
to flowing can be effectively deposited upon the tissue paper by such
methods as, for example, emulsifying the polysiloxane in surfactant or
providing the polysiloxane in solution with the aid of a solvent, such as
hexane, listed for exemplary purposes only. Particular methods for
applying polysiloxane emollients to tissue paper are discussed in more
detail hereinafter.
Preferred polysiloxanes compounds for use in the present invention are
disclosed in U.S. Pat. No. 5,059,282 (Ampulski et al), issued Oct. 22,
1991, which is incorporated herein by reference. Particularly preferred
polysiloxane compounds for use as emollients in the lotion compositions of
the present invention include phenyl-functional polymethylsiloxane
compounds (e.g., Dow Corning 556 Cosmetic-Grade Fluid:
polyphenylmethylsiloxane) and cetyl or stearyl functionalized dimethicones
such as Dow 2502 and Dow 2503 polysiloxane fluids, respectively. In
addition to such substitution with phenyl-functional or alkyl groups,
effective substitution may be made with amino, carboxyl, hydroxyl, ether,
polyether, aldehyde, ketone, amide, ester, and thiol groups. Of these
effective substituent groups, the family of groups comprising phenyl,
amino, alkyl, carboxyl, and hydroxyl groups are more preferred than the
others; and phenyl-functional groups are most preferred.
Besides petroleum-based emollients, fatty acid ester emollients, fatty acid
ester ethoxylates, alkyl ethoxylate emollients fatty alcohol emollients,
and polysiloxanes, the emollients useful in the present invention can
include minor amounts (e.g., up to about 10% of the total emollient) of
other, conventional emollients. These other, conventional emollients
include propylene glycol, glycerine, triethylene glycol, spermaceti or
other waxes, fatty acids, and fatty alcohol ethers having from 12 to 28
carbon atoms in their fatty chain, such as stearic acid, propoxylated
fatty alcohols; glycerides, acetoglycerides, and ethoxylated glycerides of
C.sub.12 -C.sub.28 fatty acids; other fatty esters of polyhydroxy
alcohols; lanolin and its derivatives. These other emollients should be
included in a manner such that the solid or semisolid characteristics of
the lotion composition are maintained.
Other suitable emollients include the hereinbefore described liquid polyol
polyesters.
The amount of emollient that can be included in the lotion composition will
depend on a variety of factors, including the particular emollient
involved, the lotion-like benefits desired, the other components in the
lotion composition and like factors. The lotion composition can comprise
from about 5 to about 95% of the emollient. Preferably, the lotion
composition comprises from about 10 to about 90%, most preferably from
about 15 to about 85%, of the emollient.
2. Immobilizing Agent
A key component of the lotion compositions of the present invention is an
agent capable of immobilizing the liquid polyol emollient on the surface
of the paper to which the lotion composition is applied. Because the
liquid polyol emollient in the composition has a fluid consistency at
ambient temperatures experienced during processing and use (up to about
37.degree. C.), it tends to flow or migrate, even when subjected to modest
shear. When applied to a tissue paper web, especially in a melted or
molten state, the emollient will not remain primarily on the surface of
the tissue paper. Instead, the emollient will tend to migrate and flow
into the interior of the paper web.
This migration of the emollient into the interior of the web can cause
undesired debonding of the paper by interfering with the normal hydrogen
bonding that takes place between the paper fibers. This usually leads to a
decrease in tensile strength of the paper. It also means much more
emollient has to be applied to the paper web to get the desired
lubricious, lotion-like feel benefits. Increasing the level of emollient
not only increases the cost, but also exacerbates the debonding problem of
the paper.
The immobilizing agent counteracts this tendency of the emollient to
migrate or flow by keeping the emollient primarily localized on the
surface of the tissue paper web to which the lotion composition is
applied. This is believed to be due, in part, to the fact that the
immobilizing agent forms hydrogen bonds with the tissue paper web. Through
this hydrogen bonding, the immobilizing agent becomes localized on the
surface of the paper. Since the immobilizing agent is also miscible with
the emollient (or solubilized in the emollient with the aid of an
appropriate emulsifier), it entraps the emollient on the surface of the
paper as well.
It is also advantageous to "lock" the immobilizing agent on the surface of
the paper This can be accomplished by using immobilizing agents which
quickly crystallize (i.e., solidify) at the surface of the paper. In
addition, outside cooling of the treated paper via blowers, fans, etc. can
speed up crystallization of the immobilizing agent.
In addition to being miscible with (or solubilized in) the emollient, the
immobilizing agent needs to have a melting point of at least about
35.degree. C. This is so the immobilizing agent itself will not have a
tendency to migrate or flow. Preferred immobilizing agents will have
melting points of at least about 40.degree. C. Typically, the immobilizing
agent will have a melting point in the range of from about 50.degree. to
about 150.degree. C.
The viscosity of the immobilizing agent should also be as high as possible
to keep the lotion from flowing into the interior of the paper.
Unfortunately, high viscosities can also lead to lotion compositions that
are difficult to apply without processing problems. Therefore, a balance
must be achieved so the viscosities are high enough to keep the
immobilizing agent localized on the surface of the paper, but not so high
as to cause processing problems. Suitable viscosities for the immobilizing
agent will typically range from about 5 to about 200 centipoises,
preferably from about 15 to about 100 centipoises, measured at 60.degree.
C.
Suitable immobilizing agents for the present invention can comprise a
member selected from the group consisting of C.sub.14 -C.sub.22 fatty
alcohols, C.sub.12 -C.sub.22 fatty acids, and C.sub.12 -C.sub.22 fatty
alcohol ethoxylates having an average degree of ethoxylation ranging from
2 to about 30, and mixtures thereof. Preferred immobilizing agents include
C.sub.16 -C.sub.18 fatty alcohols, most preferably selected from the group
consisting of cetyl alcohol, stearyl alcohol, and mixtures thereof.
Mixtures of cetyl alcohol and stearyl alcohol are particularly preferred.
Other preferred immobilizing agents include C.sub.16 -C.sub.18 fatty
acids, most preferably selected from the group consisting of palmitic
acid, stearic acid, and mixtures thereof. Mixtures of palmitic acid and
stearic acid are particularly preferred. Still other preferred
immobilizing agents include C.sub.16 -C.sub.18 fatty alcohol ethoxylates
having an average degree of ethoxylation ranging from about 5 to about 20.
Preferably, the fatty alcohols, fatty acids and fatty alcohols are linear.
Importantly, these preferred additional immobilizing agents such as the
C.sub.16 -C.sub.18 fatty alcohols increase the rate of crystallization of
the lotion causing the lotion to crystallize rapidly onto the surface of
the substrate. Lower lotion levels can therefore be utilized or a superior
lotion feel can be delivered. Traditionally, greater amounts of lotion
were needed to generate softness because of the flow of these liquids into
the tissue.
Other types of immobilizing agents can be used either alone or in
combination with the fatty alcohols, fatty acids, and fatty alcohol
ethoxylates described above. Examples of these other types of immobilizing
agents includes polyhydroxy fatty acid esters, polyhydroxy fatty acid
amides, and mixtures thereof. Preferred esters and amides will have three
or more free hydroxy groups on the polyhydroxy moiety and are typically
nonionic in character. Because of the possible skin sensitivity of those
using paper products to which the lotion composition is applied, these
esters and amides should also be relatively mild and non-irritating to the
skin.
Suitable polyhydroxy fatty acid esters for use in the present invention
will have the formula:
##STR2##
wherein R is a C.sub.5 -C.sub.31 hydrocarbyl group, preferably straight
chain C.sub.7 -C.sub.19 alkyl or alkenyl, more preferably straight chain
C.sub.9 -C.sub.17 alkyl or alkenyl, most preferably straight chain
C.sub.11 -C.sub.17 alkyl or alkenyl, or mixture thereof; Y is a
polyhydroxyhydrocarbyl moiety having a hydrocarbyl chain with at least 2
free hydroxyls directly connected to the chain; and n is at least 1.
Suitable Y groups can be derived from polyols such as glycerol,
pentaerythritol; sugars such as raffinose, maltodextrose, galactose,
sucrose, glucose, xylose, fructose, maltose, lactose, mannose and
erythrose; sugar alcohols such as erythritol, xylitol, malitol, mannitol
and sorbitol; and anhydrides of sugar alcohols such as sorbitan.
One class of suitable polyhydroxy fatty acid esters for use in the present
invention comprises certain sorbitan esters, preferably the sorbitan
esters of C.sub.16 -C.sub.22 saturated fatty acids. Because of the manner
in which they are typically manufactured, these sorbitan esters usually
comprise mixtures of mono-, di-, tri-, etc. esters. Representative
examples of suitable sorbitan esters include sorbitan palmitates (e.g.,
SPAN 40), sorbitan stearates (e.g., SPAN 60), and sorbitan behenates, that
comprise one or more of the mono-, di- and tri-ester versions of these
sorbitan esters, e.g., sorbitan mono-, di- and tri-palmitate, sorbitan
mono-, di- and tri-stearate, sorbitan mono-, di and tri-behenate, as well
as mixed tallow fatty acid sorbitan mono-, di- and tri-esters. Mixtures of
different sorbitan esters can also be used, such as sorbitan palmitates
with sorbitan stearates. Particularly preferred sorbitan esters are the
sorbitan stearates, typically as a mixture of mono-, di- and tri-esters
(plus some tetraester) such as SPAN 60, and sorbitan stearates sold under
the trade name GLYCOMUL-S by Lonza, Inc. Although these sorbitan esters
typically contain mixtures of mono-, di- and tri-esters, plus some
tetraester, the mono- and di-esters are usually the predominant species in
these mixtures.
Another class of suitable polyhydroxy fatty acid esters for use in the
present invention comprises certain glyceryl monoesters, preferably
glyceryl monoesters of C.sub.16 -C.sub.22 saturated fatty acids such as
glyceryl monostearate, glyceryl monopalmitate, and glyceryl monobehenate.
Again, like the sorbitan esters, glyceryl monoester mixtures will
typically contain some di- and triester. However, such mixtures should
contain predominantly the glyceryl monoester species to be useful in the
present invention.
Another class of suitable polyhydroxy fatty acid esters for use in the
present invention comprise certain sucrose fatty acid esters, preferably
the C.sub.12 -C.sub.22 saturated fatty acid esters of sucrose. Sucrose
monoesters and diesters are particularly preferred and include sucrose
mono- and di-stearate and sucrose mono- and di-laurate.
Suitable polyhydroxy fatty acid amides for use in the present invention
will have the formula:
##STR3##
wherein R.sup.1 is H, C.sub.1 -C.sub.4 hydrocarbyl, 2-hydroxyethyl,
2-hydroxypropyl, methoxyethyl, methoxypropyl or a mixture thereof,
preferably C.sub.1 -C.sub.4 alkyl, methoxyethyl or methoxypropyl, more
preferably C.sub.1 or C.sub.2 alkyl or methoxypropyl, most preferably
C.sub.1 alkyl (i.e., methyl) or methoxypropyl; and R.sup.2 is a C.sub.5
-C.sub.31 hydrocarbyl group, preferably straight chain C.sub.7 -C.sub.19
alkyl or alkenyl, more preferably straight chain C.sub.9 -C.sub.17 alkyl
or alkenyl, most preferably straight chain C.sub.11 -C.sub.17 alkyl or
alkenyl, or mixture thereof; and Z is a polyhydroxyhydrocarbyl moiety
having a linear hydrocarbyl chain with at least 3 hydroxyls directly
connected to the chain. See U.S. Pat. No. 5,174,927 (Honsa), issued Dec.
29, 1992 (herein incorporated by reference) which discloses these
polyhydroxy fatty acid amides, as well as their preparation.
The Z moiety preferably will be derived from a reducing sugar in a
reductive amination reaction; most preferably glycityl. Suitable reducing
sugars include glucose, fructose, maltose, lactose, galactose, mannose,
and xylose. High dextrose corn syrup, high fructose corn syrup, and high
maltose corn syrup can be utilized, as well as the individual sugars
listed above. These corn syrups can yield mixtures of sugar components for
the Z moiety.
The Z moiety preferably will be selected from the group consisting of
--CH.sub.2 --(CHOH).sub.n --CH.sub.2 OH, --CH(CH.sub.2
OH)--›(CHOH).sub.n-1 !--CH.sub.2 OH, --CH.sub.2 OH--CH.sub.2
--(CHOH).sub.2 (CHOR.sub.3)(CHOH)--CH.sub.2 OH, where n is an integer from
3 to 5, and R.sup.3 is H or a cyclic or aliphatic monosaccharide. Most
preferred are the glycityls where n is 4, particularly --CH.sub.2
--(CHOH).sub.4 --CH.sub.2 OH.
In the above formula, R.sup.1 can be, for example, N-methyl, N-ethyl,
N-propyl, N-isopropyl, N-butyl, N-2-hydroxyethyl, N-methoxypropyl or
N-2-hydroxypropyl. R.sup.2 can be selected to provide, for example,
cocamides, stearamides, oleamides, lauramides, myristamides, capricamides,
palmitamides, tallowamides, etc. The Z moiety can be 1-deoxyglucityl,
2-deoxyfructityl, 1-deoxymaltityl, 1-deoxylactityl, 1-deoxygalactityl,
1-deoxymannityl, 1-deoxymaltotriotityl, etc.
The most preferred polyhydroxy fatty acid amides have the general formula:
##STR4##
wherein R.sup.1 is methyl or methoxypropyl; R.sup.2 is a C.sub.11
-C.sub.17 straight-chain alkyl or alkenyl group. These include
N-lauryl-N-methyl glucamide, N-lauryl-N-methoxypropyl glucamide,
N-cocoyl-N-methyl glucamide, N-cocoyl-N-methoxypropyl glucamide,
N-palmityl-N-methoxypropyl glucamide, N-tallowyl-N-methyl glucamide, or
N-tallowyl-N-methoxypropyl glucamide.
As previously noted, some of the immobilizing agents require an emulsifier
for solubilization in the emollient. This is particularly the case for
certain of the glucamides such as the N-alkyl-N-methoxypropyl glucamides
having HLB values of at least about 7. Suitable emulsifiers will typically
include those having HLB values below about 7. In this regard, the
sorbitan esters previously described, such as the sorbitan stearates,
having HLB values of about 4.9 or less have been found useful in
solubilizing these glucamide immobilizing agents in petrolatum. Other
suitable emulsifiers include steareth-2 (polyethylene glycol ethers of
stearyl alcohol that conform to the formula CH.sub.3 (CH.sub.2).sub.17
(OCH.sub.2 CH.sub.2).sub.n OH, where n has an average value of 2),
sorbitan tristearate, isosorbide laurate, and glyceryl monostearate. The
emulsifier can be included in an amount sufficient to solubilize the
immobilizing agent in the emollient such that a substantially homogeneous
mixture is obtained. For example, an approximately 1:1 mixture of
N-cocoyl-N-methyl glucamide and petrolatum that will normally not melt
into a single phase mixture, will melt into a single phase mixture upon
the addition of 20% of a 1:1 mixture of Steareth-2 and sorbitan
tristearate as the emulsifier.
Other types of ingredients that can be used as immobilizing agents, either
alone, or in combination with the above-mentioned immobilizing agents,
include waxes such as carnauba, beeswax, candelilla, paraffin, ceresin,
esparto, ouricuri, rezowax, and other known waxes. Preferably the wax is a
paraffin wax. An example of a particularly preferred paraffin wax is
Parrafin S.P. 434 from Strahl and Pitsch Inc. P.O. Box 1098 West Babylon,
N.Y. 11704.
Other suitable immobilizing agents include the hereinbefore described solid
polyol polyesters, with the sucrose polybehenates being preferred.
The amount of immobilizing agent that should be included in the lotion
composition will depend on a variety of factors, including the particular
emollient involved, the particular immobilizing agent involved, whether an
emulsifier is required to solubilize the immobilizing agent in the
emollient, the other components in the lotion composition and like
factors. The lotion composition can comprise from about 5 to about 95% of
the immobilizing agent. Preferably, the lotion composition comprises from
about 5 to about 50%, most preferably from about 10 to about 40%, of the
immobilizing agent.
3. Optional Hydrophilic Surfactant
In many instances, lotion compositions according to the present invention
will be applied to tissue paper webs that will be used as toilet tissue.
In such cases, it is highly desirable that the paper web treated with the
lotion composition be sufficiently wettable. Depending upon the particular
immobilizing agent used in the lotion composition of the present
invention, an additional hydrophilic surfactant (or a mixture of
hydrophilic surfactants) may, or may not, be required to improve
wettability. For example, some immobilizing agents, such as
N-cocoyl-N-methoxypropyl glucamide have HLB values of at least about 7 and
are sufficiently wettable without the addition of hydrophilic surfactant.
Other immobilizing agents such as the C.sub.16 -C.sub.18 fatty alcohols
having HLB values below about 7 will require addition of hydrophilic
surfactant to improve wettability when the lotion composition is applied
to diaper topsheets. Similarly, a hydrophobic emollient such as petrolatum
will require the addition of a hydrophilic surfactant.
Suitable hydrophilic surfactants will be miscible with the emollient and
the immobilizing agent so as to form homogeneous mixtures. Because of
possible skin sensitivity of those using paper products to which the
lotion composition is applied, these surfactants should also be relatively
mild and non-irritating to the skin. Typically, these hydrophilic
surfactants are nonionic to be not only non-irritating to the skin, but
also to avoid other undesirable effects on the tissue paper, e.g.,
reductions in tensile strength.
Suitable nonionic surfactants may be substantially nonmigratory after the
lotion composition is applied to the tissue paper web and will typically
have HLB values in the range of from about 4 to about 20, preferably from
about 7 to about 20. To be nonmigratory, these nonionic surfactants will
typically have melt temperatures greater than the temperatures commonly
encountered during storage, shipping, merchandising, and use of tissue
paper products, e.g., at least about 30.degree. C. In this regard, these
nonionic surfactants will preferably have melting points similar to those
of the immobilizing agents previously described.
Suitable nonionic surfactants for use in lotion compositions of the present
invention include alkylglycosides; alkylglycoside ethers as described in
U.S. Pat. No. 4,011,389 (Langdon, et al), issued Mar. 8, 1977;
alkylpolyethoxylated esters such as Pegosperse 1000MS (available from
Lonza, Inc., Fair Lawn, N.J.), ethoxylated sorbitan mono-, di- and/or
tri-esters of C.sub.12 -C.sub.18 fatty acids having an average degree of
ethoxylation of from about 2 to about 20, preferably from about 2 to about
10, such as TWEEN 60 (sorbitan esters of stearic acid having an average
degree of ethoxylation of about 20) and TWEEN 61 (sorbitan esters of
stearic acid having an average degree of ethoxylation of about 4), and the
condensation products of aliphatic alcohols with from about 1 to about 54
moles of ethylene oxide. The alkyl chain of the aliphatic alcohol is
typically in a straight chain (linear) configuration and contains from
about 8 to about 22 carbon atoms. Particularly preferred are the
condensation products of alcohols having an alkyl group containing from
about 11 to about 22 carbon atoms with from about 2 to about 30 moles of
ethylene oxide per mole of alcohol. Examples of such ethoxylated alcohols
include the condensation products of myristyl alcohol with 7 moles of
ethylene oxide per mole of alcohol, the condensation products of coconut
alcohol (a mixture of fatty alcohols having alkyl chains varying in length
from 10 to 14 carbon atoms) with about 6 moles of ethylene oxide. A number
of suitable ethoxylated alcohols are commercially available, including
TERGITOL 15-S-9 (the condensation product of C.sub.11 -C.sub.15 linear
alcohols with 9 moles of ethylene oxide), marketed by Union Carbide
Corporation; KYRO EOB (condensation product of C.sub.13 -C.sub.15 linear
alcohols with 9 moles of ethylene oxide), marketed by The Procter & Gamble
Co., the NEODOL brand name surfactants marketed by Shell Chemical Co., in
particular NEODOL 25-12 (condensation product of C.sub.12 -C.sub.15 linear
alcohols with 12 moles of ethylene oxide) and NEODOL 23-6.5T (condensation
product of C.sub.12 -C.sub.13 linear alcohols with 6.5 moles of ethylene
oxide that has been distilled (topped) to remove certain impurities), and
especially the PLURAFAC brand name surfactants marketed by BASF Corp., in
particular PLURAFAC A-38 (a condensation product of a C.sub.18 straight
chain alcohol with 27 moles of ethylene oxide). (Certain of the
hydrophilic surfactants, in particular ethoxylated alcohols such as NEODOL
25-12, can also function as alkyl ethoxylate emollients). Other examples
of preferred ethoxylated alcohol surfactants include ICI's class of Brij
surfactants and mixtures thereof, with Brij 72 (i.e., Steareth-2) and Brij
76 (i.e., Steareth-10) being especially preferred. Also, mixtures of cetyl
alcohol and stearyl alcohol ethoxylated to an average degree of
ethoxylation of from about 10 to about 20 may also be used as the
hydrophilic surfactant.
Another type of suitable surfactant for use in the present invention
includes Aerosol OT, a dioctyl ester of sodium sulfosuccinic acid marketed
by American Cyanamid Company.
Still another type of suitable surfactant for use in the present invention
includes silicone copolymers such as General Electric SF 1188 (a copolymer
of a polydimethylsiloxane and a polyoxyalkylene ether) and General
Electric SF 1228 (a silicone polyether copolymer). These silicone
surfactants can be used in combination with the other types of hydrophilic
surfactants discussed above, such as the ethoxylated alcohols. These
silicone surfactants have been found to be effective at concentrations as
low as 0.1%, more preferably from about 0.25 to about 1.0%, by weight of
the lotion composition.
The amount of hydrophilic surfactant required to increase the wettability
of the lotion composition to a desired level will depend upon the HLB
value and level of immobilizing agent used, the HLB value of the
surfactant used and like factors. The lotion composition can comprise from
about 1 to about 50% of the hydrophilic surfactant when needed to increase
the wettability properties of the composition. Preferably, the lotion
composition comprises from about 1 to about 25%, most preferably from
about 10 to about 20%, of the hydrophilic surfactant when needed to
increase wettability.
4. Other Optional Components
Lotion compositions can comprise other optional components typically
present in emollient, creams, and lotions of this type. These optional
components include water, skin soothing agents or anti-inflammatories such
as aloe vera or panthenol or mixtures thereof, viscosity modifiers,
perfumes, disinfectant antibacterial actives, pharmaceutical actives, film
formers, deodorants, opacifiers, astringents, solvents and the like. In
addition, stabilizers or antioxidants can be added to enhance the shelf
life of the lotion composition such as cellulose derivatives, proteins and
lecithin. All of these materials are well known in the art as additives
for such formulations and can be employed in appropriate amounts in the
lotion compositions of the present invention.
C. Treating Tissue Paper With Lotion Composition
In preparing lotioned paper products according to the present invention,
the lotion composition is applied to at least one surface of a tissue
paper web. Any of a variety of application methods that evenly distribute
lubricious materials having a molten or liquid consistency can be used.
Suitable methods include spraying, printing (e.g., flexographic printing),
coating (e.g., gravure coating), extrusion, or combinations of these
application techniques, e.g. spraying the lotion composition on a rotating
surface, such as a calender roll, that then transfers the composition to
the surface of the paper web. The lotion composition can be applied either
to one surface of the tissue paper web, or both surfaces. Preferably, the
lotion composition is applied to both surfaces of the paper web.
The manner of applying the lotion composition to the tissue paper web
should be such that the web does not become saturated with the lotion
composition. If the web becomes saturated with the lotion composition,
there is a greater potential for debonding of the paper to occur, thus
leading to a decrease in the tensile strength of the paper. Also,
saturation of the paper web is not required to obtain the softness and
lotion-like feel benefits from the lotion composition of the present
invention. Particularly suitable application methods will apply the lotion
composition primarily to the surface, or surfaces of the paper web.
The lotion composition can be applied to the tissue paper web after the web
has been dried, i.e. a "dry web" addition method. The lotion composition
is applied in an amount of from about 0.1 to about 30% by weight of the
tissue paper web. Preferably, the lotion composition is applied in an
amount of from about 0.3 to about 20% by weight of the tissue paper web,
most preferably from about 0.5 to about 16% by weight of the web. Such
relatively low levels of lotion composition are adequate to impart the
desired softness and lotion-like feel benefits to the tissue paper, yet do
not saturate the tissue paper web to such an extent that absorbency,
wettability and particularly, strength, are substantially affected.
The lotion composition can also be applied nonuniformly to the surface(s)
of the tissue paper web. By "nonuniform" is meant that the amount, pattern
of distribution, etc. of the lotion composition can vary over the surface
of the paper. For example, some portions of the surface of the tissue
paper web can have greater or lesser amounts of lotion composition,
including portions of the surface that do not have any lotion composition
on it.
The lotion composition can be applied to the tissue paper web at any point
after it has been dried. For example, the lotion composition can be
applied to the tissue paper web after it has been creped from a Yankee
dryer, but prior to calendering, i.e., before being passed through
calender rolls. The lotion composition can also be applied to the paper
web after it has passed through such calender rolls and prior to being
wound up on a parent roll. Usually, it is preferred to apply the lotion
composition to the tissue paper as it is being unwound from a parent roll
and prior to being wound up on smaller, finished paper product rolls.
The lotion composition is typically applied from a melt thereof to the
tissue paper web. Since the lotion composition melts at significantly
above ambient temperatures, it is usually applied as a heated coating to
the tissue paper web. Typically, the lotion composition is heated to a
temperature in the range from about 35.degree. to about 100.degree. C.,
preferably from 40.degree. to about 90.degree. C., prior to being applied
to the tissue paper web. Once the melted lotion composition has been
applied to the tissue paper web, it is allowed to cool and solidify to
form solidified coating or film on the surface of the paper.
In applying lotion compositions of the present invention to tissue paper
webs, gravure coating and extrusion coating methods are preferred. FIG. 1
illustrates one such preferred method involving gravure coating. Referring
to FIG. 1, a dried tissue web 1 is unwound from parent tissue roll 2
(rotating in the direction indicated by arrow 2a) and advanced around
turning roll 4. From turning roll 4, web 1 is advanced to offset-gravure
coating station 6 where the lotion composition is then applied to both
sides of the web. After leaving station 6, web 1 becomes a lotioned web
indicated by 3. Lotioned web 3 is then advanced around turning roll 8 and
then wound up on lotioned tissue parent roll 10 (rotating in the direction
indicated by arrow 10a).
Station 6 comprises a pair of linked offset-gravure presses 12 and 14.
Press 12 consists of a lower gravure cylinder 16 and an upper offset
cylinder 18; press 14 similarly consists of a lower gravure cylinder 20
and an upper offset cylinder 22. Gravure cylinders 16 and 20 each have a
specific etched cell pattern and size, and each have a chrome plated
surface, while offset cylinders 18 and 22 each have a smooth polyurethane
rubber surface. The size of the cell volume of the gravure roll will
depend upon the desired coat weight, line speed, and lotion viscosity.
Both the gravure and offset cylinders are heated to keep the lotion
molten. These gravure and offset cylinders rotate in the directions
indicated by arrows 16a, 18a, 20a and 22a, respectively. As shown in FIG.
1, offset cylinders 18 and 22 are directly opposite and parallel to each
other and provide a nip area indicated by 23 through which web 1 passes.
Positioned beneath gravure cylinders 16 and 20 are fountain trays 24 and
26, respectively. Hot, molten (e.g., 65.degree. C.) lotion composition is
pumped into each of these heated trays 24 and 26 to provide reservoirs of
the molten lotion composition, as indicated arrows by 30 and 32,
respectively. As gravure cylinders 16 and 20 rotate in the directions
indicated by arrows 16a and 20a within reservoirs 30 and 32, they pick up
a quantity of molten lotion composition. Excess lotion on each of the
gravure cylinders 16 and 20 is then removed by doctor blades 34 and 36,
respectively.
The lotion composition remaining in the heated gravure cylinder cells 16
and 20 is then transferred to heated offset cylinders 18 and 22 (rotating
in the opposite direction as indicated by arrows 18a and 22b) in nip areas
38 and 40 between the respective pairs of cylinders. The lotion
composition transferred to offset cylinders 18 and 22 is then
simultaneously transferred to both sides of web 1. The amount of lotion
composition transferred to web 1 can be controlled by: (1) adjusting the
width of nip area 23 between offset cylinders 18 and 22; and/or (2)
adjusting the width of nip areas 38 and 40 between gravure/offset cylinder
pairs 16/18 and 20/22.
FIG. 2 illustrates an alternative preferred method involving slot extrusion
coating. Referring to FIG. 2, a dried tissue web 101 is unwound from
parent tissue roll 102 (rotating in the direction indicated by arrow 102a)
and then advanced around turning roll 104. From turning roll 104, web 101
is advanced to slot extrusion coating station 106 where the lotion
composition is then applied to both sides of the web. After leaving
station 106, web 101 becomes a lotioned web indicated by 103. Lotioned web
103 is then wound up on lotioned tissue parent roll 110 (rotating in the
direction indicated by arrow 110a).
Station 106 comprises a pair of spaced slot extruders 112 and 114. Extruder
112 has an elongated slot 116 and a web contacting surface 118; extruder
114 similarly has an elongated slot 120 and a web contacting surface 122.
As shown in FIG. 2, extruders 112 and 114 are oriented such that surface
118 is in contact with one side of web 101, while surface 122 is in
contact with the other side of web 101. Hot, molten (e.g., 65.degree. C.)
lotion composition is pumped to each of extruders 112 and 114 and is then
extruded through slots 116 and 120, respectively.
As web 101 passes over the heated surface 118 of extruder 112 and reaches
slot 116, the molten lotion composition extruded from slot 116 is applied
to the side of web 101 in contact with surface 118. Similarly, as web 101
passes over heated surface 122 of extruder 114 and reaches slot 120, the
molten lotion composition extruded from slot 120 is applied to the side of
web 101 in contact with surface 122. The amount of lotion composition
transferred to web 101 is controlled by: (1) the rate at which the molten
lotion composition is extruded from slots 116 and 122; and/or (2) the
speed at which web 101 travels while in contact with surfaces 118 and 122.
SPECIFIC ILLUSTRATIONS OF THE PREPARATION OF LOTIONED TISSUE PAPER
ACCORDING TO THE PRESENT INVENTION
The following are specific illustrations of treating tissue paper with
lotion compositions in accordance with the present invention:
Ingredient Descriptions
1. Dow Corning (Midland, Mich.) 556 cosmetic
fluid--polyphenylmethylsiloxane
2. Dow Corning (Midland, Mich.) 2503 silicone wax--primarily (89%)
dimethyl, methyloctadecylsiloxane
3. Polyol polyesters (sucrose polyesters of fatty acids (SEFA))--Procter &
Gamble Co., Cincinnati, Ohio
Liquid polyol polyester in the following examples--SEFA Cottonate (sucrose
polycottonate):
______________________________________
Ester Chain Length:Number Double Bonds
(carbon units) Weight %
______________________________________
C14 0.2
C16 13.6
C17 0.1
C18:0 7.0
C18:1 51.8
C18:2 25.8
C18:3 0.4
C:20 0.3
C:22 0.5
______________________________________
Solid polyol polyester in the following examples--SEFA Behenate (sucrose
polybehenate):
______________________________________
Ester Chain Length:Number Double Bonds
(carbon units) Weight %
______________________________________
C:14 0.1
C:16 3.9
C:17 0.0
C:18:0 1.5
C:18:1 5.9
C:18:2 6.6
C:20 3.0
C:22 77.1
C:24 1.5
______________________________________
4. White Protopet.RTM. 1S (white petrolatum made by Witco Corp.)
5. Cetearyl Alcohol (a mixed linear C.sub.16 -C.sub.18 primary alcohol made
by the Procter & Gamble Company under the name TA-1618)
6. Steareth-10 (Brij 76, a C.sub.18 linear alcohol ethoxylate having an
average degree of ethoxylation of 10, made by ICI America)
7. Sorbitan Mono-Stearate (Glycomul-S, made by Lonza)
8. N-cocoyl-N-methyl glucamide (prepared according to U.S. Pat. No.
5,174,927)
EXAMPLE 1
A. Preparation of Lotion Compositions
A water free lotion composition (Lotion A) is made by mixing the following
melted (i.e., liquid) components together: Dow Corning (Midland, Mich.)
2503 silicone wax, SEFA cottonate (sucrose polycottonate made by The
Procter & Gamble Co.), SEFA behenate (sucrose polybehenate made by The
Procter & Gamble Co.). The weight percentages of these components are
shown in Table I below:
TABLE I
______________________________________
Component Weight %
______________________________________
Dow Corning 2503 25
SEFA cottonate 50
SEFA behenate 25
______________________________________
B. Preparation of Lotioned Tissue by Hot Melt Spraying
Lotion Composition A is placed into a heated tank operating at a
temperature of 145.degree. F. The composition is subsequently sprayed
(using a Dynatec E84B1758 spray head, operating at a temperature of
160.degree. F. and an atomization pressure of 2.40 psig) onto the tissue.
Add-on level=3.0 g/m.sup.2.
EXAMPLE 2
A. Preparation of Lotion Composition
A water free lotion composition (Lotion B) is made by mixing the following
melted (i.e., liquid) components together: Dow Corning (Midland, Mich.)
556 silicone cosmetic fluid, Dow Corning (Midland, Mich.) 2503 silicone
wax, SEFA cottonate (sucrose polycottonate made by The Procter & Gamble
Co.), Glycomul-S (sorbitan monostearate made by Lonza). The weight
percentages of these components are shown in Table II below:
TABLE II
______________________________________
Component Weight %
______________________________________
Dow Corning 556 15
Dow Corning 2503 15
SEFA cottonate 40
Glycomul-S 30
______________________________________
B. Preparation of Lotioned Tissue by Hot Melt Spraying
Lotion Composition B is placed into a heated tank operating at a
temperature of 145.degree. F. The composition is subsequently sprayed
(using a Dynatec E84B1758 spray head, operating at a temperature of
160.degree. F. and an atomization pressure of 2.40 psig) onto the tissue.
Add-on level=9.0 g/m.sup.2.
EXAMPLE 3
A. Preparation of Lotion Composition
A water free lotion composition (Lotion C) is made by mixing the following
melted (i.e., liquid) components together: SEFA cottonate (sucrose
polycottonate made by The Procter & Gamble Co.), SEFA behenate (sucrose
polybehenate made by The Procter & Gamble Co.). The weight percentages of
these components are shown in Table III below:
TABLE III
______________________________________
Component Weight %
______________________________________
SEFA cottonate 85
SEFA behenate 15
______________________________________
B. Preparation of Lotioned Tissue by Hot Melt Spraying
Lotion Composition C is placed into a heated tank operating at a
temperature of 145.degree. F. The composition is subsequently sprayed
(using a Dynatec E84B1758 spray head, operating at a temperature of
160.degree. F. and an atomization pressure of 2.40 psig) onto the tissue.
Add-on level=4.7 g/m.sup.2.
EXAMPLE 4
A. Preparation of Lotion Composition
A water free lotion composition (Lotion D) is made by mixing together the
melted (i.e., liquid) components in the weight percentages shown in Table
IV below. The components are combined at room temperature in a 1 quart
plastic container. The container is sealed and placed in an oven at
70.degree. C. until all components are melted. This melted mass is
mixed/shaken thoroughly to produce a homogenous mixture. The resulting
lotion composition is maintained in a 60.degree. C. oven until ready for
use.
TABLE IV
______________________________________
Component Weight %
______________________________________
SEFA cottonate 25
White Protopet .RTM. 1S
25
TA-1618 18
N-cocoyl-N-methyl
30
glucamide
Brij 76 2
______________________________________
B. Preparation of Lotioned Tissue by Hot Melt Spraying
Melted Lotion D is placed into a PAM 600S Spraymatic hot melt spray gun
operating at a temperature of 65.degree. C. A 12 inch by 12 inch sheet of
tissue paper substrate is spray coated at a level of 0.5 g/m.sup.2 on each
side of the substrate. The lotioned tissue is placed in a 70.degree. C.
convection oven for 30 seconds after each side is sprayed to remove
volatile components, and to insure a more even coating of the lotion onto
the paper fibers.
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